For removing bees from a large opening (tree). I use a piece of plywood
slightly wider than the base of the screen cone that I am using and a little
longer than the length of the tree opening.
 
I mount this over the opening and then use a truck tire tube cut to size to
cover the openings on either side of the plywood.
 
I have never had any luck using the plastic tubing as the bees kept finding
the way back in after a couple of weeks, even with the small 3/8" tubing.
 
Ralph Harrison
Western CT Beekeepers Asociation